Harnessing immune cells to enhance β-cell mass in type 1 diabetes

2016 ◽  
Vol 64 (1) ◽  
pp. 14-20 ◽  
Author(s):  
Ercument Dirice ◽  
Rohit N Kulkarni

Type 1 diabetes is characterized by early β-cell loss leading to insulin dependence in virtually all patients with the disease in order to maintain glucose homeostasis. Most studies over the past few decades have focused on limiting the autoimmune attack on the β cells. However, emerging data from patients with long-standing diabetes who continue to harbor functional insulin-producing cells in their diseased pancreas have prompted scientists to examine whether proliferation of existing β cells can be enhanced to promote better glycemic control. In support of this concept, several studies indicate that mononuclear cells that infiltrate the islets have the capacity to trigger proliferation of islet cells including β cells. These observations indicate the exciting possibility of identifying those mononuclear cell types and their soluble factors and harnessing their ability to promote β-cell growth concomitant with autoimmune therapy to prevent the onset and/or halt the progression of the disease.

2021 ◽  
Vol 11 ◽  
Author(s):  
Jon D. Piganelli ◽  
Mark J. Mamula ◽  
Eddie A. James

Due to their secretory function, β cells are predisposed to higher levels of endoplasmic reticulum (ER) stress and greater sensitivity to inflammation than other cell types. These stresses elicit changes in β cells that alter their function and immunogenicity, including defective ribosomal initiation, post-translational modifications (PTMs) of endogenous β cell proteins, and alternative splicing. Multiple published reports confirm the presence of not only CD8+ T cells, but also autoreactive CD4+ T cells within pancreatic islets. Although the specificities of T cells that infiltrate human islets are incompletely characterized, they have been confirmed to include neo-epitopes that are formed through stress-related enzymatic modifications of β cell proteins. This article summarizes emerging knowledge about stress-induced changes in β cells and data supporting a role for neo-antigen formation and cross-talk between immune cells and β cells that provokes autoimmune attack - leading to a breakdown in tissue-specific tolerance in subjects who develop type 1 diabetes.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Adrian Villalba ◽  
Silvia Rodriguez-Fernandez ◽  
David Perna-Barrull ◽  
Rosa-Maria Ampudia ◽  
Laia Gomez-Muñoz ◽  
...  

Abstract Type 1 diabetes is an autoimmune disease caused by the destruction of the insulin-producing β-cells. To revert type 1 diabetes, the suppression of the autoimmune attack should be combined with a β-cell replacement strategy. It has been previously demonstrated that liraglutide, a glucagon-like peptide-1 receptor agonist, restores β-cell mass in type 1 diabetes, via α-cell transdifferentiation and neogenesis. We report here that treatment with liraglutide does not prevent type 1 diabetes in the spontaneous non-obese diabetic (NOD) mouse model, but it tends to reduce leukocytic islet infiltration. However, in combination with an immunotherapy based on tolerogenic liposomes, it is effective in ameliorating hyperglycaemia in diabetic NOD mice. Importantly, liraglutide is not detrimental for the tolerogenic effect that liposomes exert on dendritic cells from patients with type 1 diabetes in terms of membrane expression of molecules involved in antigen presentation, immunoregulation and activation. Moreover, the in vivo effect of the combined therapy was tested in mice humanised with peripheral blood mononuclear cells from patients with type 1 diabetes, showing no adverse effects in leukocyte subsets. In conclusion, the combination therapy with liraglutide and a liposome-based immunotherapy is a promising candidate strategy for type 1 diabetes.


2020 ◽  
Author(s):  
David G. Ramirez ◽  
Awaneesh K. Upadhyay ◽  
Vinh T. Pham ◽  
Mark Ciccaglione ◽  
Mark A Borden ◽  
...  

AbstractType 1 diabetes (T1D) results from immune infiltration and destruction of insulin-producing β-cells within the pancreatic islets of Langerhans (insulitis), resulting in loss of glucose homeostasis. Early diagnosis during pre-symptomatic T1D would allow for therapeutic intervention prior to substantial loss of β-cell mass at T1D onset. There are limited methods to track the progression of insulitis and β-cell mass decline in pre-symptomatic T1D. During insulitis, the islet microvasculature increases permeability, such that sub-micron sized particles can extravasate and accumulate within the islet microenvironment. Ultrasound is a widely deployable and cost-effective clinical imaging modality. However, conventional microbubble contrast agents are restricted to the vasculature. Sub-micron sized nanodroplet (ND) phasechange agents can be vaporized into micron-sized bubbles; serving as a circulating microbubble precursor. We tested if NDs extravasate into the immune-infiltrated islet microenvironment. We performed ultrasound contrast-imaging following ND infusion in NOD mice and NOD;Rag1ko controls, and tracked diabetes development. We measured the biodistribution of fluorescently labeled NDs, with histological analysis of insulitis. Ultrasound contrast signal was elevated in the pancreas of 10w NOD mice following ND infusion and vaporization, but was absent in both the non-infiltrated kidney of NOD mice and pancreas of Rag1ko controls. High contrast elevation also correlated with rapid diabetes onset. In pancreata of NOD mice, infiltrated islets and nearby exocrine tissue were selectively labeled with fluorescent NDs. Thus, contrast ultrasound imaging with ND phase-change agents can detect insulitis prior to diabetes onset. This will be important for monitoring disease progression to guide and assess preventative therapeutic interventions for T1D.SignificanceThere is a need for imaging methods to detect type1 diabetes (T1D) progression prior to clinical diagnosis. T1D is a chronic disease that results from autoreactive T cells infiltrating the islet of Langerhans and destroying insulin-producing β-cells. Overt disease takes years to present and is only diagnosed after significant β-cells loss. As such, the possibility of therapeutic intervention to preserve β-cell mass is hampered by an inability to follow pre-symptomatic T1D progression. There are immunotherapies that can delay T1D development. However identifying ‘at risk’ individuals, and tracking whether therapeutic interventions are impacting disease progression, prior to T1D onset, is lacking. A method to detect insulitis and β-cell mass decline would present an opportunity to guide therapeutic treatments to prevent T1D.


2016 ◽  
Vol 64 (1) ◽  
pp. 7-13 ◽  
Author(s):  
Mario R Ehlers

Type 1 diabetes (T1D) is a chronic autoimmune disease that leads to destruction of pancreatic β cells, lifelong dependence on insulin, and increased morbidity and mortality from diabetes-related complications. Preservation of residual β cells at diagnosis is a major goal because higher levels of endogenous insulin secretion are associated with better short- and long-term outcomes. For the past 3 decades, a variety of immune interventions have been evaluated in the setting of new-onset T1D, including nonspecific immunosuppression, pathway-specific immune modulation, antigen-specific therapies, and cellular therapies. To date, no single intervention has produced durable remission off therapy in most treated patients, but the field has gained valuable insights into disease mechanisms and potential immunologic correlates of success. In particular, T-cell–directed therapies, including therapies that lead to partial depletion or modulation of effector T cells and preservation or augmentation of regulatory T cells, have shown the most success and will likely form the backbone of future approaches. The next phase will see evaluation of rational combinations, comprising one or more of the following: an effector T-depleting or -modulating drug, a cytokine-based tolerogenic (regulatory T-cells–promoting) agent, and an antigen-specific component. The long term goal is to reestablish immunologic tolerance to β cells, thereby preserving residual β cells early after diagnosis or enabling restoration of β-cell mass from autologous stem cells or induced neogenesis in patients with established T1D.


Author(s):  
Rachana Haliyur ◽  
John T Walker ◽  
May Sanyoura ◽  
Conrad V Reihsmann ◽  
Shristi Shrestha ◽  
...  

Abstract Clinical and pathologic heterogeneity in type 1 diabetes is increasingly being recognized. Findings in the islets and pancreas of a 22-year-old male with 8 years of type 1 diabetes were discordant with expected results and clinical history (islet autoantibodies negative, A1C 11.9%) and led to comprehensive investigation to define the functional, molecular, genetic, and architectural features of the islets and pancreas in order to understand the cause of the donor’s diabetes. Examination of the donor’s pancreatic tissue found substantial, but reduced, β cell mass with some islets devoid of β cells (29.3% of 311 islets) while other islets had many β cells. Surprisingly, isolated islets from the donor pancreas had substantial insulin secretion that is uncommon for type 1 diabetes of this duration. Targeted and whole genome sequencing and analysis did not uncover monogenic causes of diabetes but did identify high-risk HLA haplotypes and a genetic risk score suggestive of type 1 diabetes. Further review of pancreatic tissue found islet inflammation and some previously described α cell molecular features seen in type 1 diabetes. By integrating analysis of isolated islets, histological evaluation of the pancreas, and genetic information, we concluded that the donor’s clinical insulin deficiency was most likely the result autoimmune-mediated β cell loss, but that the constellation of findings was not typical for type 1 diabetes. This report highlights the pathologic and functional heterogeneity that can be present in type 1 diabetes.


2020 ◽  
Author(s):  
Dipak Sarnobat ◽  
Charlotte R Moffett ◽  
Neil Tanday ◽  
Frank Reimann ◽  
Fiona M Gribble ◽  
...  

AbstractGut incretins, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP), enhance secretion of insulin in a glucose-dependent manner, predominantly by elevating cytosolic levels of cAMP in pancreatic β-cells. Successful targeting of the incretin pathway by several drugs, however, suggests the antidiabetic mechanism is likely to span beyond the acute effect on hormone secretion and include, for instance, stimulation of β-cell growth and/or proliferation. Likewise, the antidiabetic action of kidney sodium-glucose linked transporter-2 (SGLT-2) inhibitors exceeds simple increase glucose excretion. Potential reasons for these ‘added benefits’ may lie in the long-term effects of these signals on developmental aspects of pancreatic islet cells. In this work, we explored if the incretin mimetics or SGLT-2 inhibitors can affect the size of the islet α- or β-cell compartments, under the condition of β-cell stress.To that end, we utilised mice expressing YFP specifically in pancreatic α-cells, in which we modelled type 1 diabetes by injecting streptozotocin, followed by a 10-day administration of liraglutide, sitagliptin or dapagliflozin.We observed an onset of diabetic phenotype, which was partially reversed by the administration of the antidiabetic drugs. The mechanism for the reversal included induction of β-cell proliferation, due to a decrease in β-cell apoptosis and, for the incretin mimetics, transdifferentiation of α-cells into β-cells.Our data therefore emphasize the role of chronic incretin signalling in induction of α-/β-cell transdifferentiation. We conclude that incretin peptides may act directly on islet cells, making use of the endogenous local sites of ‘ectopic’ expression, whereas SGLT-2 inhibitors work via protecting β-cells from chronic hyperglycaemia.Graphical abstract


2007 ◽  
Vol 40 (2) ◽  
pp. 37-45 ◽  
Author(s):  
Thierry Brun ◽  
Benoit R Gauthier

Blood glucose homeostasis is achieved by the regulation of insulin and glucagon secretion from the pancreatic islet β- and α-cells. Diabetes mellitus, which comprises a heterogeneous group of hyperglycaemic disorders, results mainly from inadequate mass and function of islet β-cells. Autoimmune destruction of β-cells causes type 1 diabetes, while type 2 is characterized by impaired insulin secretion and is often associated with diminished insulin action on its target tissues. Interestingly, similar to type 1 diabetes, a gradual loss of β-cell mass is observed in type 2 diabetes often requiring insulin therapy. Understanding the molecular mechanism that governs β-cell mass plasticity may provide a means to develop strategies to countera,ct β-cell death while increasing replication. Of particular interest is the islet-specific transcription factor paired box4 (Pax4) that was previously shown to be indispensable for the establishment of the β-cell lineage during development. However, recent accumulating evidence now suggest that Pax4 is also crucial for mature β-cell expansion and survival in response to physiological cues and that mutations or polymorphisms are associated with both type 1 and type 2 diabetes. In contrast, aberrant expression of Pax4 confers protection against apoptosis to insulinomas, whereas it promotes cell growth in lymphocytes. This review summarizes promising new published results supporting the important function of Pax4 in mature islet β-cell physiology and its contribution to pathophysiology when deregulated.


Science ◽  
2021 ◽  
Vol 373 (6554) ◽  
pp. 510-516
Author(s):  
Jeffrey A. Bluestone ◽  
Jane H. Buckner ◽  
Kevan C. Herold

Type 1 diabetes (T1D) is an autoimmune disease in which T cells attack and destroy the insulin-producing β cells in the pancreatic islets. Genetic and environmental factors increase T1D risk by compromising immune homeostasis. Although the discovery and use of insulin have transformed T1D treatment, insulin therapy does not change the underlying disease or fully prevent complications. Over the past two decades, research has identified multiple immune cell types and soluble factors that destroy insulin-producing β cells. These insights into disease pathogenesis have enabled the development of therapies to prevent and modify T1D. In this review, we highlight the key events that initiate and sustain pancreatic islet inflammation in T1D, the current state of the immunological therapies, and their advantages for the treatment of T1D.


2017 ◽  
Vol 233 (3) ◽  
pp. 217-227 ◽  
Author(s):  
Maaike M Roefs ◽  
Françoise Carlotti ◽  
Katherine Jones ◽  
Hannah Wills ◽  
Alexander Hamilton ◽  
...  

Type 2 diabetes (T2DM) is associated with pancreatic islet dysfunction. Loss of β-cell identity has been implicated via dedifferentiation or conversion to other pancreatic endocrine cell types. How these transitions contribute to the onset and progression of T2DM in vivo is unknown. The aims of this study were to determine the degree of epithelial-to-mesenchymal transition occurring in α and β cells in vivo and to relate this to diabetes-associated (patho)physiological conditions. The proportion of islet cells expressing the mesenchymal marker vimentin was determined by immunohistochemistry and quantitative morphometry in specimens of pancreas from human donors with T2DM (n = 28) and without diabetes (ND, n = 38) and in non-human primates at different stages of the diabetic syndrome: normoglycaemic (ND, n = 4), obese, hyperinsulinaemic (HI, n = 4) and hyperglycaemic (DM, n = 8). Vimentin co-localised more frequently with glucagon (α-cells) than with insulin (β-cells) in the human ND group (1.43% total α-cells, 0.98% total β-cells, median; P < 0.05); these proportions were higher in T2DM than ND (median 4.53% α-, 2.53% β-cells; P < 0.05). Vimentin-positive β-cells were not apoptotic, had reduced expression of Nkx6.1 and Pdx1, and were not associated with islet amyloidosis or with bihormonal expression (insulin + glucagon). In non-human primates, vimentin-positive β-cell proportion was larger in the diabetic than the ND group (6.85 vs 0.50%, medians respectively, P < 0.05), but was similar in ND and HI groups. In conclusion, islet cell expression of vimentin indicates a degree of plasticity and dedifferentiation with potential loss of cellular identity in diabetes. This could contribute to α- and β-cell dysfunction in T2DM.


2008 ◽  
Vol 36 (3) ◽  
pp. 321-327 ◽  
Author(s):  
Decio L. Eizirik ◽  
Fabrice Moore ◽  
Daisy Flamez ◽  
Fernanda Ortis

Accumulating evidence indicates that β-cells die by apoptosis in T1DM (Type 1 diabetes mellitus). Apoptosis is an active gene-directed process, and recent observations suggest that β-cell apoptosis depends on the parallel and/or sequential up- and down-regulation of hundreds of genes controlled by key transcription factors such as NF-κB (nuclear factor κB) and STAT-1 (signal transducer and activator of transcription 1). Understanding the regulation of these gene networks, and how they modulate β-cell death and the ‘dialogue’ between β-cells and the immune system, will require a systems biology approach to the problem. This will hopefully allow the search for a cure for T1DM to move from a ‘trial-and-error’ approach to one that is really mechanistically driven.


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